This invention relates generally to automotive trim members and more particularly to methods for injection molding automotive trim members. Conventionally molded automotive trim members are typically made utilizing one of two processes. In one process, an extruded core is inserted into the mold cavity and a pigmented resin is injected around it. The injected resin fills the cavity to create a molded trim member having the desired color and surface texture. Another common process involves molding the entire trim member first and subsequently painting the trim member. Both of these processes are relatively inefficient since two separate steps are utilized to mold a support member and thereafter apply a show surface. There are also disadvantages pertaining to quality of appearance and ease of manufacture of parts made by such processes. For example, one disadvantage of inserting a core member into a mold and injecting pigmented resin around it is that the pigmented resin may not flow properly through the mold, causing discontinuities in coloring such as swirls, streaks or the like. Another disadvantage is that when liquid resin comes in contact with surfaces forming the mold cavity or with seams in a mold cavity, imperfections are formed on the exterior surface of the trim member giving it a poor appearance. An additional disadvantage includes having to place end caps on the ends of the trim members to conceal discontinuities which occur at the end portions of the trim member.
With regard to painting a molded member, paint can be unevenly distributed over the extrusion surface. Paint is easily chipped and scratched, and subject to tearing if the trim member is dented, twisted, bent or otherwise deflected. These types of members are typically solid, and therefore are heavier, and tend to have a sink problem when there are thick cross sections that cool unevenly. Thus, it is desirable to provide an automotive trim member having a backing or core member with an outer layer that provides a show surface. It is also desirable to produce this trim member with a single injection process. Furthermore, it is desirable to reduce the mass of the trim member and to reduce mold pressure during the molding process.